If Bunny Girl Senpai were to get a dub, it wouldn't be handled by Funimation, but Aniplex. I think it may get dubbed seeing as Aniplex's been dubbing nicher titles in recent years. However, that won't happen soon. Probably 2019 if we're being optimistic.

EDIT: Index S3 is confirmed to have a simuldub. Here's the source. Looks like Funimation truly was saving it for last. So, that's it for this simuldub season.